Answer:

Explanation:
= Permittivity of free space = 
= Distance charge traveled = 2 m
v = Velocity of electron = 420 m/s
E = Electric field
= Mass of electron = 
= Charge of electron = 
As the energy of the system is conserved we have

For an infinite non conducting sheet electric field is given by

The surface charge density is 
Answer:
Explanation:
Given
mass 

(inclination)=

Let T be the tension in the rope
From Diagram
-----------------1
where 

For block 
-----------2
From 1 & 2




Answer:
6.85 m/s
Explanation:
We can solve the problem by using the law of conservation of momentum.
In fact, since there are no external forces acting, the total momentum before and after must be conserved. So we can write:

where
is the initial mass of the car
is the initial speed of the car
is the mass of the car after the load of gravel is dropped
v2 is the final speed of the car
Solving for v2, we find

Force bc it says the ability to make stuff happen